Experimental Study on Towing Characteristics of Composite Bucket Wellhead Platform

With the rapid development of large-scale development of marginal oilfields in China,simple wellhead platforms that are simple in structure and easy to install have become an inevitable choice in the process of oilfield development.However,traditional simple wellhead platforms are often discarded after a single use.In pursuit of a more costeffective approach to developing marginal oilfields,this paper proposes a new offshore oil field development facility—an integrated bucket foundation for wellhead platform.To verify the safety of its towing behavior and obtain the dynamic response characteristics of the structure,this paper takes a bucket integrated bucket foundation for wellhead platform with a diameter of 40 m as the research object.By combining physical model tests and numerical simulations,it analyzes the static stability and dynamic response characteristics of the structure during towing,complete with the effects of the draft,wave height,wave period,and towing point height,which produce the dynamic responses of the structure under different influence factors,such as roll angle,pitch angle,heave acceleration and towing force as well as the sensibility to transport variables.The results show that the integrated bucket foundation for wellhead platform is capable of self-floating towing,and its movement is affected by the local environment,which will provide a reference for actual projects.

Dynamic Analysis Method of Offshore Jack-up Platforms in Regular and Random Waves

A jack-up platform, with its particular structure, showed obvious dynamic characteristics under complex environmental loads in extreme conditions. In this paper, taking a simplified 3-D finite element dynamic model in extreme storm conditions as research object, a transient dynamic analysis method was proposed, which was under both regular and irregular wave loads. The steps of dynamic analysis under extreme conditions were illustrated with an applied case, and the dynamic amplification factor （DAF） was calculated for each response parameter of base shear, overturning moment and hull sway. Finally, the structural response results of dynamic and static were compared and analyzed. The results indicated that the static strength analysis of the Jack-up Platforms was not enough under the dynamic loads including wave and current, further dynamic response analysis considering both computational efficiency and accuracy was necessary.

Design of A Bionic Spudcan and Analysis of Penetration and Extraction Performances for Jack-up Platform

The mechanisms of soil structure interaction have drawn much attention in the past years in the installation and operation of jack-up platform. A bionic spudcan produced by biomimetic of egg and snail shell is proposed, and the performance of the penetration and extraction are analyzed by numerical method. The geometric contour of egg and snail shell is measured, and its mathematical model is established respectively. According to the structure of existing spudcan of jack-up platform, three kinds of typical biomimetic spudcan are designed. Furthermore, numerical analysis models of biomimetic spudcan are established respectively to study the soil structure interaction mechanism in the process of penetration and extraction, and contrastive analysis of resistance characteristics are carried out. To conclude, the results show that the biomimetic spudcan facilitates the platform installation, and it is also beneficial to the improvement of the bearing capacity of spudcan.

Soil-Structure Interaction Analysis of Jack-up Platforms Subjected to Monochrome and Irregular Waves

As jack-up platforms have recently been used in deeper and harsher waters, there has been an increasing demand to understand their behaviour more accurately to develop more sophisticated analysis techniques. One of the areas of significant development has been the modelling of spudean performance, where the load-displacement behaviour of the foundation is required to be included in any numerical model of the structure. In this study, beam on nonlinear winkler foundation （BNWF） modeling--which is based on using nonlinear springs and dampers instead of a continuum soil media--is employed for this purpose. A regular monochrome design wave and an irregular wave representing a design sea state are applied to the platform as lateral loading. By using the BNWF model and assuming a granular soil under spudcans, properties such as soil nonlinear behaviour near the structure, contact phenomena at the interface of soil and spudcan （such as uplifting and rocking）, and geometrical nonlinear behaviour of the structure are studied. Results of this study show that inelastic behaviour of the soil causes an increase in the lateral displacement at the hull elevation and permanent unequal settlement in soil below the spudcans, which are increased by decreasing the friction angle of the sandy soil. In fact, spudeans and the underlying soil cause a relative fixity at the platform support, which changes the dynamic response of the structure compared with the case where the structure is assumed to have a fixed support or pinned support. For simulating this behaviour without explicit modelling of soil-structure interaction （SSI）, moment- rotation curves at the end of platform legs, which are dependent on foundation dimensions and soil characteristics, are obtained. These curves can be used in a simplified model of the platform for considering the relative fixity at the soil- foundation interface.

Collision Analysis Between Spudcan and Seabed During the Process of Jack-up Platform Lowering Jack-up Legs

In the leg-lowering process,the offshore jack-up platform is in a floating state,and the spudcan may collide with the seabed due to the platform motion in waves,thereby threatening the safety and stability of the platform.This paper first analyzed the hydrodynamic response of a jack-up platform under different sea states.Then a finite-element model was established which considered the material and geometrical nonlinearity in the structure and the nonlinear interaction between soil and structure to investigate the collision response between the spudcan and seabed during lowering jack-up legs.The results show that the dynamic response of the platform decreases and gradually tends to be stable as the wave period increases.The motion response of the platform reach the largest value when the wave period is 8 s and the wave direction is 0°.The collision angle between the spudcan and seabed has a large influence on the collision response,while the velocity of leg-lowering has little influence on the collision response.The collision response is also significantly affected by soil conditions.For clay,the increase in undrained shear strength and Young’s modulus will increase the impact force.

海上高压气田无人井口平台集输工艺流程方案比选设计

针对某海上高压气田井口压力高、井口温度低、油品凝点高、节流后易出现水合物和出油管线容易冻堵的问题,结合不同生产井节流后的压力,设置不同压力体系井口加热器以满足流体输送要求。文章研究了两种不同高压气田无人平台工艺流程方案:加热器部分降压设计方案和全部降压设计方案,比较了两种方案的技术特点及经济性,最终推荐高压气田无人井口平台采用加热器部分降压设计的工艺流程方案。

SPMT在井口平台组块滚装装船方式中的应用

针对自行式模块化运输车(Self-Propelled Modular Transporter,SPMT)滚装装船方式,以蓬莱19-3油田4腿式井口平台组块为例,在称重布置、临时支撑布置、运输抬梁布置和轴线布置等方面对SPMT装船方案进行适配性设计,在组块强度、运输抬梁强度和SPMT车板强度等方面对该方案的运输强度进行校核,并对该方案进行拓展。该方案可为后续井口平台组块装船方案设计提供参考。

自升式井口平台总体方案设计与关键技术实施

海上井口平台通常采用导管架,为有效开发海上边际油田,提出自升式井口平台理念。介绍该平台的整体方案设计、系统主要配置和应用操作,阐述其与常规自升式平台的不同之处、总体设计原则和关键技术、增加座底稳定性的做法。目前,自升式井口平台已在海上成功应用,对加快我国边际油田的开发、挖掘海上油气资源具有重要意义。

海上平台无人值守智能化井口装置及采油树的设计与应用

探讨海上平台无人值守智能化井口装置及采油树的应用情况和存在问题。在明确无人值守智能化井口的总体方案,确定智能化井口必备的实时监测、故障诊断、远程控制三大主要功能和改造、升级方向的基础上,设计平台的井口布局图,对智能化井口进行结构设计、仿真测试、尺寸优化,研发满足无人平台空间布局要求的井口装置及采油树。为确定主要模块的功能和改造要求,根据其特点和需求,对智能化井口进行详细设计和分析,并针对当前无人井口平台的技术特点,提出增强远程监测和控制技术的改进方向。

海上无人平台智能化提升分析研究

经过近几年的应用实践,无人驻守井口平台在设计、建造和生产运维方面积累了一定的经验,形成了新的认识。随着数字化、智能化技术的进步,需要进一步对无人平台设计进行优化提升,以推动生产方式、管理模式转变和数字化转型。对化学药剂自动加注方案进行了分析研究,提高了化学药剂自持周期,减少了生产操作人员现场操作的工作量。

海上无人钻井平台专用井口控制盘技术研究

传统井口控制盘远程操作功能不完善,提出无人钻井平台专用井口控制盘实现方案。通过新型推拉阀和多电磁阀系统的设计增强了该井口控制盘在远程操作和安全性上的能力,利用Amesim软件仿真模拟该控制盘的动态特性,验证了设计的可靠性和完整性。通过现场应用测试,验证了该井口控制盘功能稳定可靠。新井口控制盘可远程开启井上安全阀,为无人钻井平台的操作效率和安全性提供了解决思路。

无人平台井口装置监理质量控制应用

无人平台井口装置的质量控制是海洋石油类物资监理项目中的重点。本文分析了设备监理过程中遇见的无人平台井口装置典型质量问题,详细阐述了典型质量问题的发现过程、处理方式以及处理结果,总结了针对典型质量问题设备监理单位应采取的改进措施,为确保无人平台井口装置质量符合要求及提高产品的出厂合格率提供一定参考。

自安装井口平台在南海边际油田开发中的应用

自安装井口平台的特点是带有自由升降的桩腿,通过拖轮拖带至生产作业地点站桩生产。油田开发生命周期结束后,可拔桩浮起,再次由拖轮拖带至新的油田继续服役。相对于固定式导管架平台,可大幅降低平台安装及弃置拆除费用。自安装井口平台已在渤海油田的开发中应用多年,在南海尚属首次。为克服南海台风极端工况条件,需要解决平台在位稳性、平台长距离运输、平台与海管和井口连接抗疲劳等诸多问题。

The Calculating Model of Structural Analysis for Jack-Up Rig Legs

The selection or establishment of structural calculating model is a matter of primary importance in structural analysis. By analysing the irrationality of the calculating models used by some research organizations at home and abroad in structural analyses for truss jack-up rig legs, this paper introduces a new calculation model which is more reasonable. This model can simulate better the load situation of a rig reflecting more precisely the effects of the leg loads caused by the spring support of gearboxes of the jacking system and the secondary bending moment raised by hull displacement under extreme conditions. The rig conversion was completed in 1989. In July 1991 the rig safely stood the frontal hitting of Typhoon with the wind speed of 52 m / s, which shows that the checking on the structure is correct.

自安装井口平台桩靴结构强度分析

针对自安装井口平台需要在目标油田进行长期作业不撤离的特点,提出一种适用于自安装井口平台的无浮力式桩靴,桩靴设有新型的自适应式封堵楔块结构,通过封堵楔块运动解决平台站立状态时的桩腿浮力对平台的不利影响,使用有限元法对桩靴结构本体、封堵楔块在平台插桩和站立作业状态时的受力情况进行数值模拟分析,结果表明,新型自安装井口平台桩靴安全。

自安装井口平台外输海底管道疲劳拉伸磁记忆性能研究

为研究自安装井口平台外输海底管道在地磁激励下疲劳拉伸过程中X80钢表面磁场信号变化规律,使用MTS810 250疲劳拉伸试验机对X80钢的拉伸试样进行了不同载荷下的疲劳拉伸试验。实验过程中借助磁记忆传感器对拉伸试样表面的磁记忆信号变化进行监测,借助手持显微镜观察疲劳过程中试样疲劳破坏情况,借助扫描电镜对断裂后的断口进行分析。结果表明:磁记忆对拉伸疲劳损伤敏感,并归纳提出了以切向信号极值、切向梯度信号极值的连线斜率为特征值的X80钢拉伸疲劳损伤敏感的磁记忆检测参数体系,为磁记忆检测方法的现场应用奠定了基础。

“南海挑战号”半潜式平台移井优化方法研究

为了解决半潜式平台移井方案计算困难的问题,本文以“南海挑战号”半潜式平台为依托,开展移井优化方法研究。依据多段悬链线控制方程,考虑平台和各井口的位置关系,建立了系泊链长度与顶张力的关系集。采用非支配排序遗传算法,给出了最佳移井路线方案。选取了4组现场移井方案进行对比分析,研究结果表明:所提出的计算方案有效地节约移井所需的时间成本和人力成本。以D_(3)-D_(2)移井操作为例,与现场采用方案相比,移井前后系泊链收放总量减少了40.17%,同时平台移井过程中的平稳程度降低了76.45%,大幅度的提高了移井作业平台的效率和安全性。

海上无人井口平台消防泵选型与智能化控制方案

以渤海海域某海上无人井口平台为例,统计渤海作业船的消防能力,对渤海某海上无人井口平台依托作业船消防系统进行可行性分析。根据平台公用系统配备情况对消防泵选型方案进行优选,并提出消防泵智能化控制方案,为海上无人井口平台消防泵选型与智能化控制提供新思路。

自安装井口平台台风状态在线数据监测的研究

自安装式井口平台(WESU)作为海上边际油田的重要解决方案,已经在北部湾海域部署。其插装站立方式不同于传统导管架平台,虽然在设计参数中充分考虑了北部湾海域的天气情况,但仍然需要在台风状态下对平台关键位置参数进行数据监测。通过阐述北部湾海域某自安装井口平台在正常生产和台风状态下平台数据监测与回传的需要,提出了针对平台桩腿、导管架支撑、平台摇摆度、气象数据的监测与回传技术,能够为类似自升式平台的防台风措施提供参考。

海上井口平台无人驻守的研究和实施方法

通过分析有人值守井口平台的生产操作维护要点,结合平台生产环境,从安全性、经济性、智能化等方面考虑,在保障平台安全运行的前提下,研究合适的通信方式、远程遥控、远程配产、远程巡检方法等,实现中心平台对井口平台的远程巡检、监测、控制。通过海上井口无人值守方案的实施,实现了井口平台无人驻守的目标,延长了维护周期。